| 摘要 |
PROBLEM TO BE SOLVED: To provide a processing device capable of preventing the breakage of a tool by monitoring and controlling a contact state of a workpiece to the tool. SOLUTION: In the processing device for processing a conductive workpiece W by a conductive tool T, when the tool T contacts with the workpiece W in processing, a closed circuit C is formed in the order of tool T-workpiece W-brush 315-wire 311-main shaft housing 12-main shaft 11-tool T. An ac current is introduced to the closed circuit C by a high-frequency generator 314 and an excitation coil 312. When the contact state of the tool T to the workpiece W changes, the impedance in the circuit C changes, so that the ac current is changed. Accordingly, an induction current is generated in a detection coil 313, and using this current, the contact state can be monitored and controlled. By applying monitor conditions including light contact/heavy contact determining threshold values, the light contact state is always maintained in processing, thereby preventing the breakage of the tool T and deteriorating the processing accuracy without increasing the cutting resistance. COPYRIGHT: (C)2006,JPO&NCIPI |
